As weather conditions grow warmer, more people are heading for a cool-off at the American River.But as water levels remain low, officials are sending out a warning."Everybody needs to realize that low water doesn't necessarily mean safe water. It's still very dangerous, it's still flowing at 4,000 cubic feet a second, and even though it looks shallow, it still has a very strong current," says Captain Chris Vestal with the Sacramento Metropolitan Fire District.Those hidden currents bring added danger to people who aren't wearing life jackets, those who have had too much to drink, people who are overexposed to the heat, children — and even those who bring their own floating devices.In Sacramento County, everyone under the age of 13 must wear life jackets. Parents found in violation could face a $500 fine and jail time of up to six months. Across the county, there are 11 loaner life vest locations where people can borrow life jackets through the Kids Don't Float program.KCRA 3 spoke to Kent Hansen from American River Raft Rentals; he reminds people that when rafting the popular American River, "It's tough to say if there's a tree that's underneath the water that you may not be able to see. The problem with pool floats is that they are so thin that any type of puncture – whereas our rafts would bounce off – they're going to pop and they're not going to have any additional chambers to keep those afloat." This would make for a tough situation on a high-current day.Those warnings come as this year's water levels are making it difficult for rescue crews to respond."If we can't use our boats to access all parts of the river from all of our normal access points, it will take us longer," says Vestal.Water temperatures are another factor to consider. Exposure to cooler temperatures takes only a few minutes to affect a person even during hot days.